Cancers are one of the most common causes of death worldwide. In the case of women, the most common cancers are breast cancer, lung cancer and colorectal cancer. Particularly common in men is the development of prostate cancer, lung cancer and colorectal cancer (Jemal et al. 2009; CA Cancer J Clin; 59(4): 225-49). Common to all cancers are changes in the cell leading to uncontrolled growth thereof.
Depending on the nature and location of the tumor and depending on the disease stage, the cancer is treated by surgical removal of the tumor, chemotherapy, radiation therapy, immunotherapy or further so-called targeted therapy forms, which for example comprise treatment with monoclonal antibodies. In principle, it is possible to apply chemotherapy and radiation therapy as the sole therapy. However, depending on the disease stage of the patient, a plurality of therapy forms are often combined. For instance, a tumor is frequently first removed by surgical means and chemotherapy is then applied in order to kill any cancer cells remaining in the body. Radiation therapy can, for example, be used for first achieving shrinkage of the tumor, facilitating the subsequent surgical removal of the tumor. A combination of chemotherapy and radiation therapy (“radiochemotherapy”) is used, inter alia, in the treatment of tumors of the rectum, of the cervix, of the lungs, of the breasts, of the esophagus and in head and neck tumors.
Despite improved therapy options for cancer patients, the disease is, in a multiplicity of cases, not curable with respect to the cause. Here, the therapy may only slow the progression of the disease (Jemal et al. 2009; CA Cancer J Clin; 59(4): 225-49).
The chemotherapeutics used for the treatment of cancers and also the frequently used radiation therapy cause strong adverse effects in the patients (Ladewski et al. 2003; J Clin Oncol. 21(20): 3859-66). This can be explained by the fact that the action of chemotherapeutics and radiation therapy is not restricted to the cancer cells. There is damage to healthy cells. Especially affected are those cells which exhibit strong activity with regard to cell division, for example the cells of the mucous membranes. For example stomatitis, mucositis, emesis and diarrhea are observed. Further adverse effects affect the hematopoietic system; even nerve cells may be affected.
The strong adverse affects usually associated with a cancer therapy stress the patient and are ultimately also a codeterminant as regards to what extent or in which dose the chemotherapy or radiation therapy can be used.
There is thus a need for compositions and methods for preventing or weakening the occurrence of adverse effects in cancer therapies. This could improve the tolerance, efficacy and acceptance of the therapy by the patients. There is also a need for compositions and methods for increasing the efficacy of chemotherapy or radiation therapy. Increased efficacy allows the reduction of the doses to be used for the therapy and, as a result, also a reduction of the adverse effects associated with the therapy.